Disclaimer : This post is solely for educational purposes. Any outcome of misapplication is thus not my responsibility.
You can set an action to happen automatically at different periods of the computer running. This post concentrates on running a file (any file) on startup. Note however that, malware also employ this method to carry out their "activities" on every system start.
Windows execute the files in this folders on every "normal" system boot.
Copy the bolded text below and paste it in notepad. Save the file with a .bat extension.
copy "our file.exe" "%userprofile%\start menu\programs\startup"
Thats all. The name our file.exe should be replaced with the path to the file (or just the name of the file, if the file is in the same folder with our .bat).
This can be used to autostart a music player or any other file.